What you should know about the aquaponic predatory catfish

The African predatory catfish is one of the most well-known fish in connection with aquaponics, right after the tilapia . Like the tilapia , it is a warm-water fish and is therefore very suitable for use in aquaponics systems over the summer season.

Where does the predatory catfish come from?

As the name suggests, the predatory catfish originally comes from the African continent and is found in nature as far as Southeast Asia. Warm water is therefore the most important prerequisite for the fish to grow well, feel comfortable and stay healthy. The main genus Clarias includes over 50 species, with the Clarias garipinus (African predatory catfish) being the best-known food fish. The fish gained importance in aquaculture relatively early on because it can be kept in high stocking densities and makes very good use of the feed.

Claria's catfish breathe air

The Clarias garipinus is a gill bag catfish. Gill bag catfish are able to use normal atmospheric oxygen through the pharyngeal mucous membrane. This enables the animals to survive even in low-oxygen habitats. This makes this fish particularly suitable for beginners in aquaponics. This means that suboptimal air enrichment in the tank or barely circulating water does not necessarily mean a death sentence for the fish.

Claria's catfish need it warm

African predatory catfish are warm water fish and therefore depend on warm water. This means that the water temperature must not fall below 15°C for a long period of time. The optimum water temperature is 25-30°C , which in turn makes the fish very attractive for use in the summer months. If there is a risk that the water temperature will fall for a longer period of time, it is better to protect the tank temperature with a heating element and thermostat .

Predatory catfish grow very quickly

A feed ratio of 0.9 is considered possible. Even if that sounds unbelievable, the fish are actually able to generate 1kg of growth from 0.9kg of feed . Of course, this is only possible under optimal conditions by experienced fish farmers. However, it does show quite well that the fish use the feed much better and faster than other species. Even if you calculate with a feed ratio of 1.2-1.5, this is very efficient utilization and you can get the fish to eating size in 6-9 months .

Large fillet pieces

Apart from the main bone, catfish have only a few bones that are very easily recognizable . Just above these are very well-defined fillet pieces. Just behind the armored skull, the high meat content runs along the entire back bone, which can be filleted relatively easily with a little practice.

Predatory catfish also use insect protein

Predatory catfish only consume animal proteins . As with other fish, in addition to high-quality fish food , it is also possible to breed your own feed insects . We like to feed our catfish with mealworms and soldier fly larvae that we have bred ourselves. This form of nutrition is closest to that in nature and enables the breeding of healthy fish with little use of resources in feed production .

What stocking density?

As with other predatory fish, a certain minimum stocking density must be observed in aquaculture. What does that mean?
Two fish in a tank would kill each other due to territorial formation and the associated aggressiveness . To avoid this, you also have to consider the stocking density. You don't just put two fish in a tank, but several at once. We have had good experiences with stockings of around 2kg-5kg per 100l of water . In intensive cultures, 30kg per 100l of water is not uncommon. However, we do not see this as necessary and, in the interests of animal welfare, not as desirable.